Keywords :
Concentration of dominance; Dominance-diversity; Evenness; Logarithmic series; Richness, Species diversity; Sakaerat
บทคัดย่อ :
Species abundance in the 4 stands of each 1 ha permanent plot having different dominant and co-dominant tree species in the Sakaerat deciduous dipterocarp forest (SDDF), NE Thailand were investigated initially in 1984 for following up their changes in the long-term dynamic plots. All 4 stands exhibit a similar pattern of dominance-diversity curve justifying as the logarithmic series rather than showing other species abundance pattern. This species abundance pattern is attributable to the stand characteristics that all are composed of several tree species co-occurrences, having different habitat requirement while growing in the same habitat. Tree species diversity as determined by various indices including the evenness and richness indices demonstrate that SDDF has these different species attributes significantly among the 4 stands. The stand recognized as Shorea roxburghii-Quercus kerrii association type is the most species-rich and diverse as similarly to the Sakaerat evergreen rain forest (SERF) in the vicinity area of Sakaerat. Stand recognized as Shorea obtusa-Pterocarpus macrocarpus association type is lowest in species diversity and greatest species concentration of dominance, while all indices in other two stands: Shorea obtusa-Shorea siamensis and Shorea siamensis-Shorea roxburghii association types are intermediate. All 4 stands are found to be greatest in species diversity as compared to other stands of the same forest type in other locations in Thailand. Some environmental variables are considered to be the association factors for the species diversity variations among stands, such as soil organic matter and calcium storage in soil profile, especially in the limit and small area of less diverse topographic and climatic conditions and under the present condition that the stands are free from severe anthropogenic and environmental disturbances.
เอกสารอ้างอิง :
Sahunalu, P. (2010) Tree Species Abundance and Diversity in the Long-term Dynamic Plots of Sakaerat Deciduous Dipterocarp Forest, Northeastern Thailand. Journal of Forest Management 4(7) : 1-18
